diff --git a/absl/base/thread_annotations.h b/absl/base/thread_annotations.h
index 5f51c0c..6a7112d 100644
--- a/absl/base/thread_annotations.h
+++ b/absl/base/thread_annotations.h
@@ -34,6 +34,7 @@
 #ifndef ABSL_BASE_THREAD_ANNOTATIONS_H_
 #define ABSL_BASE_THREAD_ANNOTATIONS_H_
 
+#include "absl/base/attributes.h"
 #include "absl/base/config.h"
 // TODO(mbonadei): Remove after the backward compatibility period.
 #include "absl/base/internal/thread_annotations.h"  // IWYU pragma: export
@@ -151,8 +152,12 @@
 // Documents a function that returns a mutex without acquiring it.  For example,
 // a public getter method that returns a pointer to a private mutex should
 // be annotated with ABSL_LOCK_RETURNED.
+#if ABSL_HAVE_ATTRIBUTE(lock_returned)
 #define ABSL_LOCK_RETURNED(x) \
   ABSL_INTERNAL_THREAD_ANNOTATION_ATTRIBUTE(lock_returned(x))
+#else
+#define ABSL_LOCK_RETURNED(x)
+#endif
 
 // ABSL_LOCKABLE
 //
diff --git a/absl/debugging/internal/vdso_support.cc b/absl/debugging/internal/vdso_support.cc
index 1e8a78a..19deb3c 100644
--- a/absl/debugging/internal/vdso_support.cc
+++ b/absl/debugging/internal/vdso_support.cc
@@ -175,18 +175,6 @@
   return ret_code == 0 ? cpu : ret_code;
 }
 
-// We need to make sure VDSOSupport::Init() is called before
-// InitGoogle() does any setuid or chroot calls.  If VDSOSupport
-// is used in any global constructor, this will happen, since
-// VDSOSupport's constructor calls Init.  But if not, we need to
-// ensure it here, with a global constructor of our own.  This
-// is an allowed exception to the normal rule against non-trivial
-// global constructors.
-static class VDSOInitHelper {
- public:
-  VDSOInitHelper() { VDSOSupport::Init(); }
-} vdso_init_helper;
-
 }  // namespace debugging_internal
 ABSL_NAMESPACE_END
 }  // namespace absl
diff --git a/absl/debugging/symbolize_elf.inc b/absl/debugging/symbolize_elf.inc
index 328869f..b7f8663 100644
--- a/absl/debugging/symbolize_elf.inc
+++ b/absl/debugging/symbolize_elf.inc
@@ -83,6 +83,12 @@
 static char *argv0_value = nullptr;
 
 void InitializeSymbolizer(const char *argv0) {
+#ifdef ABSL_HAVE_VDSO_SUPPORT
+  // We need to make sure VDSOSupport::Init() is called before any setuid or
+  // chroot calls, so InitializeSymbolizer() should be called very early in the
+  // life of a program.
+  absl::debugging_internal::VDSOSupport::Init();
+#endif
   if (argv0_value != nullptr) {
     free(argv0_value);
     argv0_value = nullptr;
diff --git a/absl/strings/cord.cc b/absl/strings/cord.cc
index 8ecffc4..70c399c 100644
--- a/absl/strings/cord.cc
+++ b/absl/strings/cord.cc
@@ -493,10 +493,7 @@
 // --------------------------------------------------------------------
 // Cord::InlineRep functions
 
-// This will trigger LNK2005 in MSVC.
-#ifndef COMPILER_MSVC
 constexpr unsigned char Cord::InlineRep::kMaxInline;
-#endif  // COMPILER_MSVC
 
 inline void Cord::InlineRep::set_data(const char* data, size_t n,
                                       bool nullify_tail) {
diff --git a/absl/strings/internal/str_format/convert_test.cc b/absl/strings/internal/str_format/convert_test.cc
index 488d4cd..5ee5fbc 100644
--- a/absl/strings/internal/str_format/convert_test.cc
+++ b/absl/strings/internal/str_format/convert_test.cc
@@ -947,6 +947,88 @@
   EXPECT_EQ(format("%.21a", hex_value2), "0x1.081828384858600000000p+3");
 }
 
+TEST_F(FormatConvertTest, LongDoubleRoundA) {
+  if (std::numeric_limits<long double>::digits % 4 != 0) {
+    // This test doesn't really make sense to run on platforms where a long
+    // double has a different mantissa size (mod 4) than Prod, since then the
+    // leading digit will be formatted differently.
+    return;
+  }
+  const NativePrintfTraits &native_traits = VerifyNativeImplementation();
+  std::string s;
+  const auto format = [&](const char *fmt, long double d) -> std::string & {
+    s.clear();
+    FormatArgImpl args[1] = {FormatArgImpl(d)};
+    AppendPack(&s, UntypedFormatSpecImpl(fmt), absl::MakeSpan(args));
+    if (native_traits.hex_float_has_glibc_rounding &&
+        native_traits.hex_float_optimizes_leading_digit_bit_count) {
+      EXPECT_EQ(StrPrint(fmt, d), s);
+    }
+    return s;
+  };
+
+  // 0x8.8p+4
+  const long double on_boundary_even = 136.0;
+  EXPECT_EQ(format("%.0La", on_boundary_even), "0x8p+4");
+  EXPECT_EQ(format("%.1La", on_boundary_even), "0x8.8p+4");
+  EXPECT_EQ(format("%.2La", on_boundary_even), "0x8.80p+4");
+  EXPECT_EQ(format("%.3La", on_boundary_even), "0x8.800p+4");
+  EXPECT_EQ(format("%.4La", on_boundary_even), "0x8.8000p+4");
+  EXPECT_EQ(format("%.5La", on_boundary_even), "0x8.80000p+4");
+  EXPECT_EQ(format("%.6La", on_boundary_even), "0x8.800000p+4");
+
+  // 0x9.8p+4
+  const long double on_boundary_odd = 152.0;
+  EXPECT_EQ(format("%.0La", on_boundary_odd), "0xap+4");
+  EXPECT_EQ(format("%.1La", on_boundary_odd), "0x9.8p+4");
+  EXPECT_EQ(format("%.2La", on_boundary_odd), "0x9.80p+4");
+  EXPECT_EQ(format("%.3La", on_boundary_odd), "0x9.800p+4");
+  EXPECT_EQ(format("%.4La", on_boundary_odd), "0x9.8000p+4");
+  EXPECT_EQ(format("%.5La", on_boundary_odd), "0x9.80000p+4");
+  EXPECT_EQ(format("%.6La", on_boundary_odd), "0x9.800000p+4");
+
+  // 0x8.80001p+24
+  const long double slightly_over = 142606352.0;
+  EXPECT_EQ(format("%.0La", slightly_over), "0x9p+24");
+  EXPECT_EQ(format("%.1La", slightly_over), "0x8.8p+24");
+  EXPECT_EQ(format("%.2La", slightly_over), "0x8.80p+24");
+  EXPECT_EQ(format("%.3La", slightly_over), "0x8.800p+24");
+  EXPECT_EQ(format("%.4La", slightly_over), "0x8.8000p+24");
+  EXPECT_EQ(format("%.5La", slightly_over), "0x8.80001p+24");
+  EXPECT_EQ(format("%.6La", slightly_over), "0x8.800010p+24");
+
+  // 0x8.7ffffp+24
+  const long double slightly_under = 142606320.0;
+  EXPECT_EQ(format("%.0La", slightly_under), "0x8p+24");
+  EXPECT_EQ(format("%.1La", slightly_under), "0x8.8p+24");
+  EXPECT_EQ(format("%.2La", slightly_under), "0x8.80p+24");
+  EXPECT_EQ(format("%.3La", slightly_under), "0x8.800p+24");
+  EXPECT_EQ(format("%.4La", slightly_under), "0x8.8000p+24");
+  EXPECT_EQ(format("%.5La", slightly_under), "0x8.7ffffp+24");
+  EXPECT_EQ(format("%.6La", slightly_under), "0x8.7ffff0p+24");
+  EXPECT_EQ(format("%.7La", slightly_under), "0x8.7ffff00p+24");
+
+  // 0xc.0828384858688000p+128
+  const long double eights = 4094231060438608800781871108094404067328.0;
+  EXPECT_EQ(format("%.0La", eights), "0xcp+128");
+  EXPECT_EQ(format("%.1La", eights), "0xc.1p+128");
+  EXPECT_EQ(format("%.2La", eights), "0xc.08p+128");
+  EXPECT_EQ(format("%.3La", eights), "0xc.083p+128");
+  EXPECT_EQ(format("%.4La", eights), "0xc.0828p+128");
+  EXPECT_EQ(format("%.5La", eights), "0xc.08284p+128");
+  EXPECT_EQ(format("%.6La", eights), "0xc.082838p+128");
+  EXPECT_EQ(format("%.7La", eights), "0xc.0828385p+128");
+  EXPECT_EQ(format("%.8La", eights), "0xc.08283848p+128");
+  EXPECT_EQ(format("%.9La", eights), "0xc.082838486p+128");
+  EXPECT_EQ(format("%.10La", eights), "0xc.0828384858p+128");
+  EXPECT_EQ(format("%.11La", eights), "0xc.08283848587p+128");
+  EXPECT_EQ(format("%.12La", eights), "0xc.082838485868p+128");
+  EXPECT_EQ(format("%.13La", eights), "0xc.0828384858688p+128");
+  EXPECT_EQ(format("%.14La", eights), "0xc.08283848586880p+128");
+  EXPECT_EQ(format("%.15La", eights), "0xc.082838485868800p+128");
+  EXPECT_EQ(format("%.16La", eights), "0xc.0828384858688000p+128");
+}
+
 // We don't actually store the results. This is just to exercise the rest of the
 // machinery.
 struct NullSink {
diff --git a/absl/strings/internal/str_format/float_conversion.cc b/absl/strings/internal/str_format/float_conversion.cc
index 6eb7b9f..cafa479 100644
--- a/absl/strings/internal/str_format/float_conversion.cc
+++ b/absl/strings/internal/str_format/float_conversion.cc
@@ -738,7 +738,8 @@
 // point that is not followed by 800000..., it disregards the parity and rounds
 // up if > 8 and rounds down if < 8.
 template <typename Int>
-bool HexFloatNeedsRoundUp(Int mantissa, int final_nibble_displayed) {
+bool HexFloatNeedsRoundUp(Int mantissa, int final_nibble_displayed,
+                          uint8_t leading) {
   // If the last nibble (hex digit) to be displayed is the lowest on in the
   // mantissa then that means that we don't have any further nibbles to inform
   // rounding, so don't round.
@@ -755,11 +756,10 @@
     return mantissa_up_to_rounding_nibble_inclusive > eight;
   }
   // Nibble in question == 8.
-  uint8_t should_round_at_8 =
-      (final_nibble_displayed >= kTotalNibbles)
-          ? true
-          : (GetNibble(mantissa, final_nibble_displayed) % 2 == 1);
-  return should_round_at_8;
+  uint8_t round_if_odd = (final_nibble_displayed == kTotalNibbles)
+                             ? leading
+                             : GetNibble(mantissa, final_nibble_displayed);
+  return round_if_odd % 2 == 1;
 }
 
 // Stores values associated with a Float type needed by the FormatA
@@ -788,7 +788,7 @@
   // Index of the last nibble that we could display given precision.
   int final_nibble_displayed =
       precision_specified ? std::max(0, (kTotalNibbles - state.precision)) : 0;
-  if (HexFloatNeedsRoundUp(*mantissa, final_nibble_displayed)) {
+  if (HexFloatNeedsRoundUp(*mantissa, final_nibble_displayed, *leading)) {
     // Need to round up.
     bool overflow = IncrementNibble(final_nibble_displayed, mantissa);
     *leading += (overflow ? 1 : 0);
diff --git a/absl/time/time_test.cc b/absl/time/time_test.cc
index 6f89672..b28a99f 100644
--- a/absl/time/time_test.cc
+++ b/absl/time/time_test.cc
@@ -58,8 +58,7 @@
 // timespec ts1, ts2;
 // EXPECT_THAT(ts1, TimespecMatcher(ts2));
 MATCHER_P(TimespecMatcher, ts, "") {
-  if (ts.tv_sec == arg.tv_sec && ts.tv_nsec == arg.tv_nsec)
-    return true;
+  if (ts.tv_sec == arg.tv_sec && ts.tv_nsec == arg.tv_nsec) return true;
   *result_listener << "expected: {" << ts.tv_sec << ", " << ts.tv_nsec << "} ";
   *result_listener << "actual: {" << arg.tv_sec << ", " << arg.tv_nsec << "}";
   return false;
@@ -69,8 +68,7 @@
 // timeval tv1, tv2;
 // EXPECT_THAT(tv1, TimevalMatcher(tv2));
 MATCHER_P(TimevalMatcher, tv, "") {
-  if (tv.tv_sec == arg.tv_sec && tv.tv_usec == arg.tv_usec)
-    return true;
+  if (tv.tv_sec == arg.tv_sec && tv.tv_usec == arg.tv_usec) return true;
   *result_listener << "expected: {" << tv.tv_sec << ", " << tv.tv_usec << "} ";
   *result_listener << "actual: {" << arg.tv_sec << ", " << arg.tv_usec << "}";
   return false;
@@ -103,7 +101,7 @@
   EXPECT_EQ(a, b);
   EXPECT_EQ(a, c);
   EXPECT_EQ(b, c);
-  b = c;       // Assignment
+  b = c;  // Assignment
   EXPECT_EQ(a, b);
   EXPECT_EQ(a, c);
   EXPECT_EQ(b, c);
@@ -228,6 +226,9 @@
   constexpr absl::Time t = absl::UnixEpoch();  // Any finite time.
   static_assert(t < ifuture, "");
   static_assert(t > ipast, "");
+
+  EXPECT_EQ(ifuture, t + absl::InfiniteDuration());
+  EXPECT_EQ(ipast, t - absl::InfiniteDuration());
 }
 
 TEST(Time, FloorConversion) {
@@ -358,19 +359,21 @@
   const int64_t min_plus_1 = std::numeric_limits<int64_t>::min() + 1;
   EXPECT_EQ(min_plus_1, absl::ToUnixSeconds(absl::FromUnixSeconds(min_plus_1)));
   EXPECT_EQ(std::numeric_limits<int64_t>::min(),
-            absl::ToUnixSeconds(
-                absl::FromUnixSeconds(min_plus_1) - absl::Nanoseconds(1) / 2));
+            absl::ToUnixSeconds(absl::FromUnixSeconds(min_plus_1) -
+                                absl::Nanoseconds(1) / 2));
 
   // Tests flooring near positive infinity.
   EXPECT_EQ(std::numeric_limits<int64_t>::max(),
-            absl::ToUnixSeconds(absl::FromUnixSeconds(
-                std::numeric_limits<int64_t>::max()) + absl::Nanoseconds(1) / 2));
+            absl::ToUnixSeconds(
+                absl::FromUnixSeconds(std::numeric_limits<int64_t>::max()) +
+                absl::Nanoseconds(1) / 2));
   EXPECT_EQ(std::numeric_limits<int64_t>::max(),
             absl::ToUnixSeconds(
                 absl::FromUnixSeconds(std::numeric_limits<int64_t>::max())));
   EXPECT_EQ(std::numeric_limits<int64_t>::max() - 1,
-            absl::ToUnixSeconds(absl::FromUnixSeconds(
-                std::numeric_limits<int64_t>::max()) - absl::Nanoseconds(1) / 2));
+            absl::ToUnixSeconds(
+                absl::FromUnixSeconds(std::numeric_limits<int64_t>::max()) -
+                absl::Nanoseconds(1) / 2));
 }
 
 TEST(Time, RoundtripConversion) {
@@ -1045,15 +1048,15 @@
 
   // Checks how TimeZone::At() saturates on infinities.
   auto ci = utc.At(absl::InfiniteFuture());
-  EXPECT_CIVIL_INFO(ci, std::numeric_limits<int64_t>::max(), 12, 31, 23,
-                            59, 59, 0, false);
+  EXPECT_CIVIL_INFO(ci, std::numeric_limits<int64_t>::max(), 12, 31, 23, 59, 59,
+                    0, false);
   EXPECT_EQ(absl::InfiniteDuration(), ci.subsecond);
   EXPECT_EQ(absl::Weekday::thursday, absl::GetWeekday(ci.cs));
   EXPECT_EQ(365, absl::GetYearDay(ci.cs));
   EXPECT_STREQ("-00", ci.zone_abbr);  // artifact of TimeZone::At()
   ci = utc.At(absl::InfinitePast());
-  EXPECT_CIVIL_INFO(ci, std::numeric_limits<int64_t>::min(), 1, 1, 0, 0,
-                            0, 0, false);
+  EXPECT_CIVIL_INFO(ci, std::numeric_limits<int64_t>::min(), 1, 1, 0, 0, 0, 0,
+                    false);
   EXPECT_EQ(-absl::InfiniteDuration(), ci.subsecond);
   EXPECT_EQ(absl::Weekday::sunday, absl::GetWeekday(ci.cs));
   EXPECT_EQ(1, absl::GetYearDay(ci.cs));
@@ -1171,14 +1174,13 @@
   const int kMin = std::numeric_limits<int>::min();
   absl::Time t;
 
-  t = absl::FromDateTime(std::numeric_limits<absl::civil_year_t>::max(),
-                         kMax, kMax, kMax, kMax, kMax, utc);
+  t = absl::FromDateTime(std::numeric_limits<absl::civil_year_t>::max(), kMax,
+                         kMax, kMax, kMax, kMax, utc);
   EXPECT_EQ("infinite-future",
             absl::FormatTime(ymdhms, t, utc));  // no overflow
-  t = absl::FromDateTime(std::numeric_limits<absl::civil_year_t>::min(),
-                         kMin, kMin, kMin, kMin, kMin, utc);
-  EXPECT_EQ("infinite-past",
-            absl::FormatTime(ymdhms, t, utc));  // no overflow
+  t = absl::FromDateTime(std::numeric_limits<absl::civil_year_t>::min(), kMin,
+                         kMin, kMin, kMin, kMin, utc);
+  EXPECT_EQ("infinite-past", absl::FormatTime(ymdhms, t, utc));  // no overflow
 
   // Check normalization.
   EXPECT_TRUE(absl::ConvertDateTime(2013, 10, 32, 8, 30, 0, utc).normalized);